Dry-kiln for lumber.



J. M. LEAVBR.

DRY KILN FOR LUMBER APPLICATION FILED JULY 10,1911.

Patented Sept. 24, 1911;

7 SHBETSSHEET 1.

Jib/1166.111; Lew/e1;

J. M. LBAVER.

DRY KILN FOR LUMBER.

APPLIGATION FILED JULY 10,

Patented Sept. 24, 1912,

7 SHEETSSHEBT 2.

w K M fi I J. M. LEAVER.

DRY KILN FOB. LUMBER.

APPLXOATION FILED JULY 10, 1911.

Patented Sept. 24-, 1912.

alto um J. M. LBAVBR.

DRY KILN FOR LUMBER.

APPLICATION FILED JULY 10, 1911 Patented Sept. 24, 1912.

J. M. LEAVER. DRY KILN FOR LUMBER.

APPLICATION FILED JULY 10, 1911.

Patented Sept. 24, 1912.

'] SHEETS-SHEET 5 J. M. LEAVER.

DRY KILN FOR LUMBER APPLICATION FILED JULY 10, 1911.

3 1,()39,3()1 tea bept.24,1912.

7 SHETS-SHEET 6v Jun/m5 A I. [mm '61 J. M. LEAVBR.

DRY KILN FOR LUMBER.

APPLICATION FILED JULY 1m 1911.

Patented Sept. 24, 1912.

I SHEETS-SHEET I.

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[I @(l l 6 [2 m 14107 q/qitwe oou a v Mr/I/ JAMES M. LEAVER, OF LONGBEACH, CALIFORNIA.

DRY-KILN FOR LUMBER.-

application filed m 10, 1911. senrno. $37,805.

7 '0 all wlioni it may concern:

3 Be it known that I, Jain-1s M. Leaves, a citizen of the United States, residing at 'Longbeach, in the county of Los Angeles and State of California, have invented a new and useful Dry-Kiln for Lumber, of which the followin isa specification.

The invention r ates to improvements in dry kilns for lumber.

improve the construct-ion of dry kilns, and

todncreasei the etiiciency of the same, and' to providea sim 1e and comparatively inexpensive dry kin, adapted to mix heated moist air from the kiln with cold air, which enters the-kiln from the outside. to raise the temperature ofthe incoming air, so that when thcsamestrikes the steam pipes, it

will beraised to a much highertemperat-urc than isobtainable-underthe ordinary dry ing processes where the cold air is either conducted directly to the. steam pipes or 1 simply passe? through ducts, which are exposed to the teat of the kiln, or is subjected to a preliminary heating by auxiliary steam coils,

A further object of the invention is ,to

i provide a dry kiln of this character, adapted to afford perfect control of the degree of heat, the circulation of the air and the quan .tityof moisture in the kiln, and capable of being advantageously employed either in progressive systems of drying where one end of the kiln is maintained at. a higher tem-' perature than the other, or in kilns for drying lumber in a batch or block, that is to Say,

the entire contents of the drying chamber containing a number of cars at one time.

\Vith these and other objects in view. the invention consists in the construction and novel combination of parts hereinafter fully described, illustrated in the accompanying drawings, and pointed outin the claims hereto appended; it being understood that various changes in the form, proportion, size and minor details of construction, within the scope of the claims, may he resorted to without departin from the spirgitor sacrificing-any of the ac vantages of. the invention.

In the dra 'ngst-Figure 1 is a vertical transverse sectional view of a dry kiln, constructcd in accordance with this invention. Fig. 2 is a longitudinal sectional view on the line 2-2 of Fig. 1. Fig. 3 is a longitudinal sectional view of the upper portion The object of the present invention is to of the kiln on the line 3-3 of Fig. 1. Fig.

i is a horizontal sectional view on the line Fig. 5 1s a-horizontal-sec- 4-4. of Fig. l. tional view .on the line 5-5 of Fig. 1. Fig.

6 is a transverse sectional view, illustrating another form of the invention, and taken Specification of Letters Ifatent. Patented Sept. 24, 1912.

substantially on the line (3-6 of Fig. 13.

Fig. 7 is a transverse sectionalview, taken substantially on the line 7-7 of 'Fig. 11. Fig. 8 is a transverse sectional view on the line 8-8 of Fig. 10. Fig. 9 is a longitudinal sectional view of a portion of the dry kiln on the line 99 of Fig. 8. Fig. 10 is a'longitudinal sectional view on the line 10-10 .of Fig. 8. Fig. 11 is a horizontalsectional view on theline 11-11 'of Fig. 7. Fig. 12 is a horizontal sectional view, taken substantiallv on the line 12-12 of Fig. 6a Fig. 13 is a horizontal sectional view, takensubstane- .tially on the line 13-13 of Fig. 6.

Like numerals of reference designate corresponding parts in all the figures of the drawings. r v

The. dry kiln illustrated in Figs. 1 to Sinclusive of the accompanying drawings comprises in its construction side walls 1 and 2,

and a roof 3, all of which may be constructed of any suitable material; The dry kiln, which may be constructed in a series, as indicated in Fig. 1, may of course be made with ansingle drying chamber-t, and it is provided at the top of the same with a ceiling or top wall 5, spaced from the roof 3 and composed of oppositely inclined side portions. as clearly illustrated in Fig. 1 of the drawings, but I do not wish to limit myself to an oppositely inclined top wall or ceiling, as any othcr weferred arrangement may be employed, and it mav be constructed of any suitable material. The intervening space between the top will or ceiling 5 and the roof 3 is divided hf inclined longitudinally disposed partitions 7 into a lower mix,- ing chamber 8 and upper suction chambers any preferred construction, extend from the opposite side walls of the kiln to the center of theunderside of the roof, and their outer side edges are located slightly above the side;

edges of the top wall or ceiling of thedrying chamber and provide openings 10 and 11 for connecting the mixing chamber with wert-ical .cold .air inlet ducts 12 and vertical down ducts 13, which connect the; chamber with -transverse bottom ducts or passages 14. The vertical cold air iplet 30 faces to and are adapted to split the current ducts are formed in the side walls 1, which are provided at the lower portions of the vertical ducts 12 with air inlet openings 15, the passage of the air through the openings 15 being controlled by a hinged damper 16,

or'other suitable means. The cold air is caused to travel upwardly through the vertical inlet ducts or passages by the suction in the chambers 7 with which stacks 17 and 18 communicate, the area of the stacks being sufliciently in excess of the area of the inlet openings to produce the desired draft through the passages or ducts, whereby a positive damper controlled circulation of air through the .kiln is produced. The wallsare preferably made hollow, as shown, and consist of inner and outer shells and studding 19, arranged at intervals and dividing the space between the inner and outer shells into :ducts of passages and forming dead air spaces between the passages. The top wall or ceiling is preferably supported by studding 20 to the'underside of which the top wall or ceiling is suitably secured, and the said top wall or ceiling supports substantially V-- shaped deflectors 21, located opposite the.

openings 10 and adapted to deflect the air entering the mixin chamber in order to p il'pduce a uniform distribution of the same. Q e deflectors present angular-1y disposed of air passing upward through the ducts or passages 12. The cold or incoming air after entering the mixing chamber commingles with warm moist air, which is introduced .into the mixing chamber 8 through rents 22 in the top wall or ceiling. These vents, which are preferably arranged at intervaLs at the ridge of the top wall or ceiling, may be located at any desired points, and they preferablyponsist of short ducts, tapered upwardly and extending into the mixing 0 amber from openings in the'to wall or ceiling. The draft through the kilncauses the Ir from the mixing chamber to travel do nwardlv through the ducts'or passages 13 to the ldwei transverselydisposed ducts or passages 14, which are provided with outlets 23., preferably located centrally of the space between the rails 24 of the tracks of the kiln. \Vhen the kiln is arranged in muli of the drawings. The rails 24 of the tracks are supported pon standards or posts 26 in the usual manner, and the kiln is equipped ,with heatingrpipes 27, located above the lower transverse air passages or ducts 1'1 and supportedby transversebeams 28, or other suitable means and preferably consisting of longitudinally disposed steam pipes;

but the steam or heating pipes may be arranged in' any preferred manner, as maybe readily understood. The air passing upward through the outlet openings of the lower transverse passages or ducts against the heating pipes, and its temperature is raised by the latter to a muph higher degree than is possible when cold air taken immediately from the outside atmosphere is directed-against the heating pipes, and as it is moist by the admixture of a portion of the air of the dryiu sesses greater ad dry air, it being a well recognized fact that a certain amount of moisture must be maintained in the kiln in order to keep the surface of the lumber soft and the pores opento prevent warping, checking, hollow horning, case hardening and otherinjurious results. Moisture may be supplied to the kiln by injecting live steam orexhaust steam into the same, or by any other suitable means, and as this is well known in the art and does not constitute a portion of the present invention, illustration thereof is deemed unnecessary. The kiln'may be constructed of any desired capacity, and 'in the accompanying drawings it is shown with two tracm for the reception of kiln cars' 29 upon which the lumber. or othenmaterial to be dried] is loaded. In order to direct the hot air toward the center of the lumber at the bottom, the kiln is, equipped with central and impinges chamber of the kiln, it posvantages than highly heated side deflectors 30 and 31,extendinglongitudinally of the kiln and'located centrally side walls 1 and 2. -T e deflectors are located approximately in the plane of the tracks and the heatin pipes, and the central deflector 30 is su tantiallytriangular in cross section and presents to the rising air inclined side faces 32, which diver e upwardly and are adapted to deflect the air toward the median line .of the cars andthe contents thereof. The side deflectors 31 have inclined inner side faces 33, which extend upwardly and inwardly for directing the rising air toward the center of the 'material at the bottom of the same. tral and side bottom deflectors at this point are preferably made hollow, as shown, but they may be constructed in any preferred manner. The kiln is also equipped at the upper portion with inclined deflectors 534, located'in the angles formed by the side walls and the top wall or ceiling and extending downwardly and inwardly and adapted to re-direct the rising air intocontact with the material at the outer sides thereof. The kiln is provided at intervals. with outlet suction devices 35, depending at intervals from the top wall or ceiling of the kiln, and designed to be located at suitable intervals beneath the ridge of the said to", Walton ceilingand tapered downwardly.

. 100 of the spaces between the tracks and at the The depending suction ducts-35 are connect- 1 ing chamber 4 are closed by suitable jdOOIPS 51, which may be of any 'preferredcons'trnced at their upper ends with the suction .-chambers 9 by oppositetransvcrse branch ducts or passages 36, arranged at an inclination and extending upwardly and outwardly in opposite directionsfrom the cen trally partitions 7, and communicating at their -outer' ends with the suction chambers 9 through suitable openings in the said parti-.

I rods are connected. The suction chambers 9, which extend substantially the entire length of the'kiln, are connectedat their ends with'thehooded stacks or chimneys 17 and 18 by means of suitable damper controlled outlets 41 and 42, located directly beneath the said stacks or chimneys 17 and 18. The stack or chimney 18, which is twicethe capacity of the stack or chimney 17, is'dipassages 44 and 45, which are connected at.

vided a central partition '43 to form two their lower ends with the adjacent kiln members, as clearly illustrated in Fig. 1 of thedrawings. The dampers 46 for controlling the passage of air from the suction chamhers to the stack are hinged at 47 and are designedto operated-by any suitable means, By adjusting the dampers of the chimneys, the strength of the draft and the consequent circulation of. air through the kiln is controlled, and this in connection .with 'the control of the temperature and moisture of the drying chambers through the dampers of the outlet suction ducts will enable the kiln to be employed for the pro gressive drying of lumber, or for the simultaneous drying of the entire contents of-the kiln. The'kiln is also provided at each end with an upper transverse chamber or duct 48, extending-downwardly from the roof to the plane of the side edges of the top wall or ceiling, and provided below the intermediateportion of the ceiling with suitable damper cont-rolled outlet openings 49 to per- 'mit. the moist air to pass directly from the drying chamber through the said transverse end chambers or ducts 48 to the chimneys or stacks. This will enable more complete oontrol of the heat and moisture to be obtained, and thedamper 50 for controllingv the passage of air through the opening 49 is hin'gedat the top and maybe operated by any suitable means. The ends of the dryarra'nged outlet suction ducts to thetion. s.

In Figs. 6 1o 13 inclusive of thedrawings is illustrated another form of lnverttion, in

which the dry vkiln comprisesrinits con.- struction side walls 52, a roof.53,- and atop wall or ceiling 54 composed of inclined side portions, extending upward from the-sidewalls at points below the roof-53 to a point beneath the center or median: line thereof 'and forming upper longitudinal mixing chambers 55. The mixing. chambers 55,

which receive heated air and vapor from the the lateral branches, which are' located at suitable intervals, connect the' longitudinal cold air ducts with vertical ducts or passages 61, arranged within theside walls 52 of the kiln and connected at their upper ends with upper inclined ducts or'passages 62, disposed transversely-of the inclined side portions of the topwall or ceiling and extending upwardly from theside edges thereof across the same to within a short distance of the ridge and provided at their upper ends with outlet openings63, communicating with the mixing chambers 55, as clearly illustrated in Figiti of the drawings The kiln is equipped at the: u-ppercnds of the inclined transversely disposed ducts or passages 62 with approximately V-shaped defiectors 64, having'a'ngularly disposed sides or wings and arranged to splitand deflect the currents of air for distributing the same uniformly throughoutthe mixing chambers, and to causethe incoming air to commingle thoroughly with the heated air and moisture of the drying chamber of the kiln. The mixing chambers 55 are also connected by down ducts or passages 65 with lower trans verse ducts or passages'66, located within the floor 67 and having outlet openings 68, arranged centrally beneath the space between thefrails 69. The outlet openings 68 extend through the floor 67, which also eferably constitutes the top wall of the ongit-udinal cold air duct- 57. The lower transverse air ducts are provided at the inner sides of the outlet openings 68 with inclined partitions 70, which assist in directing the airthrough the openings 68.

The rails of the tracks are supported upon asthe heating pipes 27 heretofore described, being supported by transverse beams 73.

The preliminary heating of the air by the central deflector 75 is triangular in cross section, and presents upwardly diverging side faces before directing the air to the material contained on the kiln cars 76. The side deflectors 75, which are mounted upon the side walls of the kiln, are approximately V-shapcd in cross section and have inclined sides, which extend upwardly and inwardly for directing the heated air toward the material under treatment. Upper deflectors 77 constructed similar to the upper deflectors 36 are provided for also directing the air toward the material and to prevent a free passage of air upward through the space between the lumber and the side walls of the kiln. The deflectors 77, which are dis posed longitudinally of the kiln, extend downwardly and inwardly at the angles formed by the side walls and the inclined portions of the top wall or ceiling. The hotair and moisture from the drying chamber pass out to the chimneys or stacks 7S and 79 through outlet suction ducts 80, arranged vertically in the side walls 52 of the kiln and baring lower openings 81 and upper openings 82. arranged at intervals throughout the length of the side walls of the kiln, and the lower openings (ffllllllllllllcate with the drying chamber. and the upper openings are in communication with the longitudinal suction chambers 33, located at oppositesides of the kiln above the outer portions of the top wall r ceiling and at the outer sides of the mixing chambers 55. The stacks or chimneys, which eonnnunirate with the suction chainers at the. ends thereof, have sutlicient area to cause a positive circulation of air through the passages of the kiln, and the draft and the. consequent escape of the heated air and moisture are controlled by suitable dampers 84, arranged at the lower portions of passages85, which connect the suction chambers with the chimneys or stacks. The dampers are preferably pivotally mounted, the. pivots or pintles being provided with exterior crank arms 86 to which rods 87 are connected.

The dry kiln may be arranged in a series of multiples, as indicated in the accompanying drawings, and each kiln or mem- The suction outlet ducts are her is distinct from'the'others, and the circulation, temperature and moisture are under complete control through the adjust ment of the dampers 84 of the chimneys or stacks. 7

So far as I am aware it is new to mix in a. chamber orlduct cold air from the outside atmosphere with heated moist air from the drying chamber before the cold air is intro duced under the heating pipes.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A dry kiln including a drying chamber, a mixing chamber or duct located at the top of the kilnfmeans for conducting the air from the outside atmosphere to the mixing chamber or duct, means contained within the kiln for mixing a portion of the heated moist air with the cold air to cause the same to commingle in the mixing cham-' her before the air from the outside atmos phere is introduced into the-drying chamber, means for conducting the mixture from the mixing chamber or duct to the drying chamber, and heating means located within the kiln and arranged in the path of the said mixture, and a chimney or stack communicating with the drying chamber for producing a circulation through the kiln.

2. A dry kiln including a drying chamber, a mixing chamber located above the dryingchamber, separate ducts connecting the mixing chamber with the outside atmosphere and with the lower portions of the drying chamber. ineans contained within the kiln for introducing a portion of the heated moist. air of the drying chamber into the mixing chamber to cause the same to commingle. with the cold air before the latter is introduced into the drying chamber, and heating means located within the drying chamber and arranged in the path of the air entering the same.

3. A dry kiln including a drying chamber, a mixing chamber, separate means for connecting the mixing chamber with the outside atmosphere and with the drying chamber. means contained within the kiln for inixing a portion of the heated moist airof the drying chamber with the cold air to cause the same to commingle in the mi-x ing chamber before the air from the outside atmosphere is introduced into the drying chamber, achimney or stack, and asuction chamber connected with the drying chamber and with the chimney or stack for conveying away the heated air and moisture.

4. A dry kiln including a drying chamber, a mixin chamber communicating with the drying c iamber and'adapted to receive heated air and moisture from the same, ducts connecting the mixing chamber with the outside atmosphere and with the drying chamber at the bottom thereof, heating i. a means located within the drying chamber in the path of the air entering the same, and

causinga draft or circulation through the ltiln,."and means for controlling the draft throu h. the stack or chimney.

5. Xdry kiln including adrying chamher, a mixing chamber located above the drying chamberand communicating there- '.'with so as to receive heated air and moisture therefrom, separate ducts connecting the mixing chamber with the outside atmosphere and with the drying chamber, means fbr heating the air entering the drying chamber, a suction chamber also located above the dr ing chamber and connected therewith, and a chimney, or stack communicating'with the suctionchamber. ,1 6, A dry kiln including a. drying cham beria mix ng chamber located at the top ofmeans for connecting the mixing.

the kiln, chamber with the outside'atmosphere, ducts located at the bottom of the drying cham.- her and having outlets communicating therewith, 'm'eansjfoi: connectin the ducts at the bottom of the drying cham r with the mixing chamber', meanscontained within the M gfor introducing a portion of the,heatcd moist aii'of the drying chamber into the chamber-to cause the same to com,- mingle "with thecold air before the latter is introduced into the drying chamber, and

heating. means located within the drying chamber and arranged in the path ofthe air entering the same; N

7. A kiln"includ irfg a drying chamber, a mixing chamber-located atthe top of the kiln, means fo'r connecting the mixing chamber with the outside atmosphere, ducts located at the bottom of 'the drying chamber and having outletsco nmunicating therewith, means for connecting the ducts at the bottom of the drying chamber with the mixing chamber, means contained within the kiln for introducing a portion of the heated moist air of the drying chamber into the mixing chamber to cause the same to conr mingle with-the cold air before the latter is introduced into the drying chamber, healing means located within the drying chaur her and agrangcd in the path of the air ontering the same, and deflectors locatcdaborc the heating means for directing the air upon the material to be dried.

8. Adry kiln including a drying chamber, a mixing chaaiiber communicating witlr the drying chamber and adapted to receive. heated air and-moisture from the same, means for connecting the mixing chamber with the qutside atmosphere, ducts arranged at thc bottomof the drying chamber and having outlet openings for discharging air into the same, means for connecting the bottom duets with the mixing chamber, heating means located within the drying chamber in the path of the air entering the same, side deflectors located at opposite sides of the drying chamber and having upwardly and inwardly inclined faces, and a deflector located between the side deflectors and having upwardly diverging side faces.

9. A dry kiln including a drying chamber,

a mixing chamber cormnunicating with the drying chamber and adapted to receive 'heated'air and moisture from the same, means for connecting the mixing chamber with the outside atmosphere,ducts arranged at the bottom of the drying chamber and having outlet openings for discharging air into the same, means for connecting the bottom ducts with the mixing chamber, heating means located Within the drying chamber in the path of the air entering the same, tracks 'l'ocated above the heating means, anddeheated air toward the material.

10. A dry'kiln including a dryingxhamher, a mixing chamber communicating with .the drying chamber and adapted to receive .tlectors' arranged between the tracks and at vthe outer sides thereof for directing the heated air and moisture from the same,

7 meansfor connecting the m ixing chamber with the outside atmosphere, ductsarranged at the bot-tom of the drying. chamber and having outlet openings for dischargingair into the same, means for connecting the bottom ducts with the; mixing chamber,

heating means located-within the dryingehzunhcr in the path of theair entering the same, tracks located above the heatingmcans, a central deflector located at the space between the tracks and having upwardly diverging inclined side faces, and

side dcllcch'irs located at the outer sides of I the tracks and having upwardly and inwardly extending inclined faces.

11. dry kiln including a drying chamber, a mixing chamber communicating with the drying chamber and adapted to receive heated air and inoislurc from the same, HHHHS for c nnecting the mixing chamber with the outside atmosphere, ducts arranged at tho lmllmn of the drying chamber and having oullet openings for discharging air into the same. means for connecting the bottom ducls with the mixing chamber, heating nu-nns located within the drying chamher in the path of the air entering the same, tracks located above the heating means, a cent rnl deflector located at the space between theiracks and having upwardly diverging inclined far-cs. and inclincd deflectors l0- cah-d at the upper portion of thc drying" vhambcr and extending from they side walls lheroot vfor directing the heated air against the n'iatcrial.

12. A dry kiln including a drying chamber, a mixing chamber communicating with the drying chamber and adapted to receive heated air and moisture from the same, means for connecting the mixing chamber with the outside atmosphere, 'ducts arranged at the bottom of the drying chamber and having outlet openings for discharging air into the same, means .for connecting the bottom. duets with the mixing chamber, heating means located within the drying chamsite sides of the drying chamber and havingv inclined faces arranged to direct the heate air against the material.

13. A dry kiln including opposite side walls, a roof, a top wall or ceiling forming a drying chamber, an upper mixing cham ber, means contained w thin the kiln for introducing a portion of. the heated moist air walls and communicating. at their 11 per ends with the mixing chambe'r, one 0 the ducts being connected at its lower portion;

with the outside atmosphere and the: other duct communicating withthe drying chamber at the bottoii portio n thereof, and heat ing means arranged within thedrying chamber in the path of the air entering the same.

14. A dry kiln including opposite side walls, a roof, a top wall or ceiling forming a drying chamber, and an upper mixing chamber communicating with the drying chamber and adapted to receive heate air and moisture from the same, vertical ducts arranged in .the side walls and communicating at their upper ends with the mixin chamber, one of the ducts being connected at its lower portion with the outside atmosphere and the other duct communicating with the drying chamber at the bqttom portion thereof, heating means arranged with-' in the drying chamber in the path of the air entering thesame, a suction chamber located at the upper portion of the kiln and communicating with the drying chamber, and a chimney or stack connected with the suction chamber.

15. A dry kiln including oppositeside walls, a roof, atop wall or ceiling forming a drying chamber, and an upper mixing chamber communicating with the d ing chamber and adapted to receive heat/e air and moisture from the same, vertical ducts arranged in the side walls and communicating at their upper ends with the mixing "moisture from thedrying'chamber to the 'mixing cha'mber and means for connecting of the drying chamber. of the drying chamber into the mixing chamber, vertical ducts arranged in the side chamber, one of the ducts being connected at its lower portion with the outside atmosphere and the other duct communicating. with the d ing chainber at the bottom por-' tion thereo heating means arranged within the drying chamber in the path of the air entering the same, a suction chamber located abovc the top wall or ceiling and extending longitudinally of the kiln, and suction ducts arranged at intervals and connectflector arranged for splitting and spreading the current of air entering the mixing chamber, means for introducing heated air andthe mixing chamber withthe heated portion 17.;A'dry kiln including side walls hav-' ing vertical ducts, a'roof, a top wall or ceilforming adrying chamber and an upper" niixing chamberlocated above the drying receive .heated air and moisture therefrom, means for connecting the upper ends of the chamber and communicating therewith to vertical duets with the mixing chamber,

means for connecting the lower ends of some of the vertical duets with the outside atmos-' phere, and means for connecting the lower ends of the other vertical ducts with the bot tom portion of the drying chamber for discharging air into the same, and heating means arranged in the .path of the air-dis charged into the drying chamber. 7

18. A dry kiln including side walls having vertical ducts, a roof, a top .wallcr ceiling forming a drying chamber and anf iip per mixing chamber located above the drying chamber and communicating therewith to receive heated air and moisture th i from, means for-connecting the upper ei't s of the vertical duets wi h the mixing chamber, means for connecting the lower ends of some of the vertical ducts with the outside atmosphere, means for connecting the lower into the drying chamber, a longitudinal suction chamber also located. above the top wall i 'or ceiling, and outlet suction ducts or passages arranged-a1? intervals and connecting the drying chamber with the suction chamber.

' ing vertical ducts, a roof, atop wall or ceiling forming a drying chamber and an upper mixing chamber located above the drying chamber and communicating therewith to receive heated air and moisture therei "cm, means for connecting the upperends (d'jbe vertical duets with the mixing chamber, means for connecting the lower ends of some 'of the-vertical duets with the outside atmosphere, means for connecting the lower ends of the other vertical duets with the bottom portion of the drying chamber for discharging air into the same, heating means arranged in the path of the air discharged into the drying chamber, longitudinal suction chambers located at opposite sides of the kiln and arrangedabove the top wall or ceiling, outlet suction ducts arranged at intervals and connecting the drying chambers with the suction chambers, and chimneys or stacks located at the ends of" the kiln and connected with the ends of the suction chambers.

20. A dry kiln including-opposite walls, a

roof, a top;wall or ceiling connected with theside walls and forming adrying chamber and spaced from the;.-roof,fa longltudina.

' partition dividing the space above the top wall er -ceiling into a suction chamber and a mixing chamber,-the mixing chamber communicating with the drying chamber and adapted to receiveheated air and moisture therefrom, means for connecting ,the mixing chamber with the outside atmosphere and with the drying chamber, and separate means for connecting the drying chamber with the suction chamber, and a chimney or stuck connected at the bottom with the suction chamber.

21. A dry kiln including opposite walls. a roof, a top wall or ceiling connecting the side walls to form a drying chamber and spaced from the roof, longitudinal partitions dividing the space above the top wall or ceiling into 0p osite suction chambers and a mixing cham er, the latter communicating with the drying chamber and adapted I to receive heated airand moisture therefrom, means for connecting the mixmgcnamber with the outside air and with the drying chamber, and an outlet suction duct depending from the top wall or ceiling and having branches connected with the opposite suction chambers.

22. A dry kiln including opposite walls. a roof, :1 top wall orceiling connecting the walls to form a drying chamber, partitions located above the top wall or ceiling and forming opposite suction chambers and u mixing chamber. :1 vent conncctin the mixing chamber with the drying chnui ber, ducts connecting .tlumixing chamber with the out side atmos here and with the drying chamceive heat and moisture -therefrom,--du cts 'for connecting the' mixing chamber with the outsideatmosphere and with the drying chamber, a chimney or stack, a suction- .chamber communicating with the chimney or stack and connected .with the drying chamber, and damper contrplled means for 'directly connect ng the drying chamber with the chimney or stack.

24. A dry kiln including a drying. chambet, a mixing chamber communicating with the drying chamber and adapted to receive heat andmoisture therefrom, ducts for connecting the mixing chamber with the outside atmosphere and with. the drying chamber chimneys, or stacks, opposite longitudin suction chambers located above the drying i chamber and communicating with the chimneys vor stacks, outlet suction ducts connecting the suction chambers with the drying chamber, .and upper transverse ducts arranged at the ends of the'suction ducts and communic ing with the drying chamber and the chimneys or stacks to permit the heated air and moisture to pass directly to the said chimneys 0r stacks, and means for controlling the passage of air through the ducts or chambers.

25. A dry kiln includin a drying chamber, heating pipes at the ottom thereof, a mixing cham er or duct, passages for conveying cold air from the outside atmos phcrc to the mixing chamber or duct, means contained within the kiln for introducing heated moist air from the drying chamber into the mixing chamber or duct to cause the same to commingle with the cold air before the latter is introduced into the drying chamber, separate means for conducting air from the mixing chamber to apoint beneath the heating pipes, and a chimney or stack ommunicating with the drying chamber for causing a circulation through the kiln.

26. A dry kiln including a drying chamber. heating means, a mixing chamber or duct, a passage for conducting cold air from the outside atmosphere to the mixing chamber or duct, means contained within the kiln for mixing a portion of the heat d moist air of the drying chamber with the cold air and for causing the same to commingle m the mixing chamber before the air from the atmosphere is introduced into the drying chamber, separate means for conducting tbc mixed air from the mixing chamber or duct to the drying chamber, and a chimney or stuck communicating with the filndsxtending along the kiln and comin drying chamber for causing a circulation through the kiln. I

27. A dry kiln including a drying chamher, a mixing chamber arranged at the top of the drying chamber, a suction chamber also located at the'top of the drying chamicating with the said drying chamber, a pass for conducting cold air from the outsi e atmosphere to the mixing chamber,

means contained within the kiln for mixing ing the same to commingle in the mixing chamber before the air from the outsidatmosphere is introduced into the drying chamber, separate means for conducting the mixed air from the mixing chamber to the drying chamber, means for heating such cold air, and a chimney 0r stack connected with the suction chamber for causing a circulation through the kiln.

In testimony that I claim the foregoing as my o\\-'n,'I have hereto afiixecl my signature in the presence of two witnesses.

J AMES M. LEAVER. \Vitness'es:

A. M. DlVOLL, K. Lmvnn. 

